Bindi Irwin’s Dancing With The Stars partner has announced he is expecting his first child.

Professional dancer Derek Hough, 40, announced earlier this week that his wife Hayley Erbert Hough was pregnant in a video on Instagram.

“We can’t believe the biggest thing to happen to us could be so small,” the caption read.

Know the news with the 7NEWS app: Download today

In another post showing the couple holding ultrasound pictures, Derek said: “Already so loved”.

Hough won Dancing With The Stars alongside celebrity partner Bindi Irwin in 2015.

Irwin congratulated the pair on their exciting news.

“Congratulations!!!!! Hugs from our entire family,” she said.

Following in his sister’s footsteps, Robert Irwin announced in April that he would also be putting on his dancing shoes and joining the show.

“Bindi, thank you for inspiring me to take on this next adventure. Dancing With The Stars, I’m so grateful for the life-changing experience ahead,” he said at the time.

Hough was on Dancing With The Stars from 2007 to 2016, winning the show six times with his partners.

His sister is actor and dancer Julianne Hough, who also appeared on the TV show for five seasons.